Digital Printing and Coating
LaboratorySandia National Laboratories (SNL)
Capability ExpertFernando Garzon, Bryan Kaehr, Randy Schunk
Process and Manufacturing Scale-Up
Node Readiness Category2: Low-Temperature Electrolysis (LTE)
Our digital printing capability consists of a suite of direct write and coating deposition platforms (see image) including a ultra-high resolution 3D laser printer (Nanoscribe), a multi-layer registration gravure/flexo printer (GT+W), and a model-based discovery and design capability. Additionally we have die and gravure coating machines (RK). These tools provide an R&D setting to synthesize precision 3D architectures as well as multi-layer material assemblies, for example, membrane electrode assemblies (MEAs) using procedures that bridge directly to large-scale manufacturing (e.g., roll-to-roll). This capability can be used to address the suboptimal microstructure of current nonprecious catalyst MEAs where control over multiphase transport is limited to composition and thickness. Our printing/coating capability will be used to engineer layer-to-layer micro-channels and structural composition to improve gas and liquid transport without undermining electronic and ionic conductivity. This will enable unprecedented control of MEA layer morphology and the potential ability to directly print custom tailored gas diffusion layers on the MEAs. The capability could also aid in the optimization of low PGM MEAs. Gravure and related precision thin film coating technologies are amenable to a wide range of precursor viscosities and can generate precision thin films (< 1 micron) with uniformity over 10s of cm^2 with thicknesses ranging from 20 nm to > 150 microns.
The GT+W gravure/flexo printer uses a 4 in carriage assembly but can accommodate both hard and flexible substrates. RK gravure printer feeds 4 in wide flexible substrates (no larger), single pass only. Direct write, inkjet and aerosol printing tools are limited to 20-30 micron feature sizes. The Nanoscribe printer provides true 3D printing with <1 micron feature size but is limited to 3 mm heights over 100x100 mm area.
The digital printing laboratory is located at the Advanced Materials Laboratory on the University of New Mexico's south campus. It is staffed with Sandia SMEs involved in machine design and application for direct-write and roll-to-roll nano-manufacturing systems, aided by CAE scale-up and design, and material scientists focused on nanomaterial ink development. Our expertise in ink optimization and printing process modeling coupled to microstructural optimization tools will further the development of high performance, lower cost fuel cells.
The capability will be available to staff, students and visitors as it is housed at the Advance Materials Laboratory on the UNM campus.
Controllable electrode and MEA morphology and small-lot production lending to the efficiency of the materials discovery and development research priority of HydroGEN.
SNL direct write deposition platform showing successive iteration of various form factors.
1. Eastman, T. and A. Cook. Direct Write Electronics-Thick Films on LTCC. in International Symposium on Microelectronics. 2014. International Microelectronics Assembly and Packaging Society.
2. P. R. Schunk and K. Tjiptowidjojo, "Coating Science through Modeling and Simulation", Converting Quarterly, Quarter 2, 2015 (www.convertingquarterly.com).
3. H. Fan, Y. Lu, A Stump, S. T. Reed, T. Baer, P. R. Schunk, V. Luna, G. Lopez, and C. J. Brinker 2000. "Rapid prototyping of patterned functional nanostructures." Letter to Nature, 4 May 2000.